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package library;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.ScrollPaneConstants;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.TableModel;

public class PagingModel extends AbstractTableModel{
    protected int pageSize = 20;
    protected int pageOffset;
    protected Record[] data;
    protected String[] Columns;

    public PagingModel() {
    }

    public PagingModel(String[] Columns, Record record) {
        data = record.init();
        this.Columns = Columns;
        pageSize = record.getPageSize();
    }
    // Return values appropriate for the visible table part.

    @Override
    public int getRowCount() {
        return Math.min(pageSize, data.length);
    }

    @Override
    public int getColumnCount() {
        return this.Columns.length;
    }

    // Work only on the visible part of the table.
    @Override
    public Object getValueAt(int row, int col) {
        int realRow = row + (pageOffset * pageSize);
        if(realRow < data.length){
            return data[realRow].getValueAt(col);
        }
        return "";
    }

    @Override
    public String getColumnName(int col) {
        return Columns[col];
    }

    // Use this method to figure out which page you are on.
    public int getPageOffset() {
        return pageOffset;
    }

    public int getPageCount() {
        return (int) Math.ceil((double) data.length / pageSize);
    }

    // Use this method if you want to know how big the real table is . . . we
    // could also write "getRealValueAt()" if needed.
    public int getRealRowCount() {
        return data.length;
    }

    public int getPageSize() {
        return pageSize;
    }

    @Override
    public boolean isCellEditable(int rowIndex, int columnIndex) {
        return false;
    }
    
    public void setPageSize(int s) {
        if (s == pageSize) {
            return;
        }
        int oldPageSize = pageSize;
        pageSize = s;
        pageOffset = (oldPageSize * pageOffset) / pageSize;
        fireTableDataChanged();
        /*
         * if (pageSize < oldPageSize) { fireTableRowsDeleted(pageSize,
         * oldPageSize - 1); } else { fireTableRowsInserted(oldPageSize,
         * pageSize - 1); }
         */
    }

    @Override
    public Class getColumnClass(int c) {
        return getValueAt(0, c).getClass();
    }

    // Update the page offset and fire a data changed (all rows).
    public void pageDown() {
        if (pageOffset < getPageCount() - 1) {
            pageOffset++;
            fireTableDataChanged();
        }
    }

    // Update the page offset and fire a data changed (all rows).
    public void pageUp() {
        if (pageOffset > 0) {
            pageOffset--;
            fireTableDataChanged();
        }
    }

    // We provide our own version of a scrollpane that includes
    // the page up and page down buttons by default.
    public static JScrollPane createPagingScrollPaneForTable(JTable jt) {
        JScrollPane jsp = new JScrollPane(jt);
        TableModel tmodel = jt.getModel();

        // Don't choke if this is called on a regular table . . .
        if (!(tmodel instanceof PagingModel)) {
            return jsp;
        }

        // Okay, go ahead and build the real scrollpane
        final PagingModel model = (PagingModel) tmodel;
        final JButton upButton = new JButton(new ArrowIcon(ArrowIcon.UP));
        upButton.setEnabled(false); // starts off at 0, so can't go up
        final JButton downButton = new JButton(new ArrowIcon(ArrowIcon.DOWN));
        if (model.getPageCount() <= 1) {
            downButton.setEnabled(false); // One page...can't scroll down
        }

        upButton.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent ae) {
                model.pageUp();

                // If we hit the top of the data, disable the up button.
                if (model.getPageOffset() == 0) {
                    upButton.setEnabled(false);
                }
                downButton.setEnabled(true);
            }
        });

        downButton.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent ae) {
                model.pageDown();

                // If we hit the bottom of the data, disable the down button.
                if (model.getPageOffset() == (model.getPageCount() - 1)) {
                    downButton.setEnabled(false);
                }
                upButton.setEnabled(true);
            }
        });

        // Turn on the scrollbars; otherwise we won't get our corners.
        jsp.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
        jsp.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);

        // Add in the corners (page up/down).
        jsp.setCorner(ScrollPaneConstants.UPPER_RIGHT_CORNER, upButton);
        jsp.setCorner(ScrollPaneConstants.LOWER_RIGHT_CORNER, downButton);

        return jsp;
    }
}
